1 /* site.c - manage communication with a remote network site */
4 * This file is part of secnet.
5 * See README for full list of copyright holders.
7 * secnet is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 3 of the License, or
10 * (at your option) any later version.
12 * secnet is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * version 3 along with secnet; if not, see
19 * https://www.gnu.org/licenses/gpl.html.
22 /* The 'site' code doesn't know anything about the structure of the
23 packets it's transmitting. In fact, under the new netlink
24 configuration scheme it doesn't need to know anything at all about
25 IP addresses, except how to contact its peer. This means it could
26 potentially be used to tunnel other protocols too (IPv6, IPX, plain
27 old Ethernet frames) if appropriate netlink code can be written
28 (and that ought not to be too hard, eg. using the TUN/TAP device to
29 pretend to be an Ethernet interface). */
31 /* At some point in the future the netlink code will be asked for
32 configuration information to go in the PING/PONG packets at the end
33 of the key exchange. */
40 #include <sys/socket.h>
44 #include "unaligned.h"
48 #define SETUP_BUFFER_LEN 2048
50 #define DEFAULT_KEY_LIFETIME (3600*1000) /* [ms] */
51 #define DEFAULT_KEY_RENEGOTIATE_GAP (5*60*1000) /* [ms] */
52 #define DEFAULT_SETUP_RETRIES 5
53 #define DEFAULT_SETUP_RETRY_INTERVAL (2*1000) /* [ms] */
54 #define DEFAULT_WAIT_TIME (20*1000) /* [ms] */
56 #define DEFAULT_MOBILE_KEY_LIFETIME (2*24*3600*1000) /* [ms] */
57 #define DEFAULT_MOBILE_KEY_RENEGOTIATE_GAP (12*3600*1000) /* [ms] */
58 #define DEFAULT_MOBILE_SETUP_RETRIES 30
59 #define DEFAULT_MOBILE_SETUP_RETRY_INTERVAL (1*1000) /* [ms] */
60 #define DEFAULT_MOBILE_WAIT_TIME (10*1000) /* [ms] */
62 #define DEFAULT_MOBILE_PEER_EXPIRY (2*60) /* [s] */
64 #define PEERKEYS_SUFFIX_MAXLEN (sizeof("~incoming")-1)
66 /* Each site can be in one of several possible states. */
69 SITE_STOP - nothing is allowed to happen; tunnel is down;
70 all session keys have been erased
71 -> SITE_RUN upon external instruction
72 SITE_RUN - site up, maybe with valid key
73 -> SITE_RESOLVE upon outgoing packet and no valid key
74 we start name resolution for the other end of the tunnel
75 -> SITE_SENTMSG2 upon valid incoming message 1 and suitable time
76 we send an appropriate message 2
77 SITE_RESOLVE - waiting for name resolution
78 -> SITE_SENTMSG1 upon successful resolution
79 we send an appropriate message 1
80 -> SITE_SENTMSG2 upon valid incoming message 1 (then abort resolution)
81 we abort resolution and
82 -> SITE_WAIT on timeout or resolution failure
84 -> SITE_SENTMSG2 upon valid incoming message 1 from higher priority end
85 -> SITE_SENTMSG3 upon valid incoming message 2
86 -> SITE_WAIT on timeout
88 -> SITE_SENTMSG4 upon valid incoming message 3
89 -> SITE_WAIT on timeout
91 -> SITE_SENTMSG5 upon valid incoming message 4
92 -> SITE_WAIT on timeout
94 -> SITE_RUN upon valid incoming message 5
95 -> SITE_WAIT on timeout
97 -> SITE_RUN upon valid incoming message 6
98 -> SITE_WAIT on timeout
99 SITE_WAIT - failed to establish key; do nothing for a while
100 -> SITE_RUN on timeout
105 #define SITE_RESOLVE 2
106 #define SITE_SENTMSG1 3
107 #define SITE_SENTMSG2 4
108 #define SITE_SENTMSG3 5
109 #define SITE_SENTMSG4 6
110 #define SITE_SENTMSG5 7
113 #define CASES_MSG3_KNOWN LABEL_MSG3: case LABEL_MSG3BIS
117 int32_t site_max_start_pad = 4*4;
119 static cstring_t state_name(uint32_t state)
122 case 0: return "STOP";
123 case 1: return "RUN";
124 case 2: return "RESOLVE";
125 case 3: return "SENTMSG1";
126 case 4: return "SENTMSG2";
127 case 5: return "SENTMSG3";
128 case 6: return "SENTMSG4";
129 case 7: return "SENTMSG5";
130 case 8: return "WAIT";
131 default: return "*bad state*";
137 #define LOG_UNEXPECTED 0x00000001
138 #define LOG_SETUP_INIT 0x00000002
139 #define LOG_SETUP_TIMEOUT 0x00000004
140 #define LOG_ACTIVATE_KEY 0x00000008
141 #define LOG_TIMEOUT_KEY 0x00000010
142 #define LOG_SEC 0x00000020
143 #define LOG_STATE 0x00000040
144 #define LOG_DROP 0x00000080
145 #define LOG_DUMP 0x00000100
146 #define LOG_ERROR 0x00000400
147 #define LOG_PEER_ADDRS 0x00000800
148 #define LOG_SIGKEYS 0x00001000
150 static struct flagstr log_event_table[]={
151 { "unexpected", LOG_UNEXPECTED },
152 { "setup-init", LOG_SETUP_INIT },
153 { "setup-timeout", LOG_SETUP_TIMEOUT },
154 { "activate-key", LOG_ACTIVATE_KEY },
155 { "timeout-key", LOG_TIMEOUT_KEY },
156 { "security", LOG_SEC },
157 { "state-change", LOG_STATE },
158 { "packet-drop", LOG_DROP },
159 { "dump-packets", LOG_DUMP },
160 { "errors", LOG_ERROR },
161 { "peer-addrs", LOG_PEER_ADDRS },
162 { "sigkeys", LOG_SIGKEYS },
163 { "default", LOG_SETUP_INIT|LOG_SETUP_TIMEOUT|
164 LOG_ACTIVATE_KEY|LOG_TIMEOUT_KEY|LOG_SEC|LOG_ERROR|LOG_SIGKEYS },
165 { "all", 0xffffffff },
170 /***** TRANSPORT PEERS declarations *****/
172 /* Details of "mobile peer" semantics:
174 - We use the same data structure for the different configurations,
175 but manage it with different algorithms.
177 - We record up to mobile_peers_max peer address/port numbers
178 ("peers") for key setup, and separately up to mobile_peers_max
181 - In general, we make a new set of addrs (see below) when we start
182 a new key exchange; the key setup addrs become the data transport
183 addrs when key setup complets.
185 If our peer is mobile:
187 - We send to all recent addresses of incoming packets, plus
188 initially all configured addresses (which we also expire).
190 - So, we record addrs of good incoming packets, as follows:
191 1. expire any peers last seen >120s ("mobile-peer-expiry") ago
192 2. add the peer of the just received packet to the applicable list
193 (possibly evicting the oldest entries to make room)
194 NB that we do not expire peers until an incoming packet arrives.
196 - If the peer has a configured address or name, we record them the
197 same way, but only as a result of our own initiation of key
198 setup. (We might evict some incoming packet addrs to make room.)
200 - The default number of addrs to keep is 3, or 4 if we have a
201 configured name or address. That's space for two configured
202 addresses (one IPv6 and one IPv4), plus two received addresses.
204 - Outgoing packets are sent to every recorded address in the
205 applicable list. Any unsupported[1] addresses are deleted from
206 the list right away. (This should only happen to configured
207 addresses, of course, but there is no need to check that.)
209 - When we successfully complete a key setup, we merge the key setup
210 peers into the data transfer peers.
212 [1] An unsupported address is one for whose AF we don't have a
213 socket (perhaps because we got EAFNOSUPPORT or some such) or for
214 which sendto gives ENETUNREACH.
216 If neither end is mobile:
218 - When peer initiated the key exchange, we use the incoming packet
221 - When we initiate the key exchange, we try configured addresses
222 until we get one which isn't unsupported then fixate on that.
224 - When we complete a key setup, we replace the data transport peers
225 with those from the key setup.
229 - We can't tell when local network setup changes so we can't cache
230 the unsupported addrs and completely remove the spurious calls to
231 sendto, but we can optimise things a bit by deprioritising addrs
232 which seem to be unsupported.
234 - Use only configured addresses. (Except, that if our peer
235 initiated a key exchange we use the incoming packet address until
236 our name resolution completes.)
238 - When we send a packet, try each address in turn; if addr
239 supported, put that address to the end of the list for future
240 packets, and go onto the next address.
242 - When we complete a key setup, we replace the data transport peers
243 with those from the key setup.
249 struct comm_addr addr;
253 /* configuration information */
254 /* runtime information */
256 transport_peer peers[MAX_PEER_ADDRS];
259 /* Basic operations on transport peer address sets */
260 static void transport_peers_clear(struct site *st, transport_peers *peers);
261 static int transport_peers_valid(transport_peers *peers);
262 static void transport_peers_copy(struct site *st, transport_peers *dst,
263 const transport_peers *src);
265 /* Record address of incoming setup packet; resp. data packet. */
266 static void transport_setup_msgok(struct site *st, const struct comm_addr *a);
267 static void transport_data_msgok(struct site *st, const struct comm_addr *a);
269 /* Initialise the setup addresses. Called before we send the first
270 * packet in a key exchange. If we are the initiator, as a result of
271 * resolve completing (or being determined not to be relevant) or an
272 * incoming PROD; if we are the responder, as a result of the MSG1. */
273 static bool_t transport_compute_setupinit_peers(struct site *st,
274 const struct comm_addr *configured_addrs /* 0 if none or not found */,
275 int n_configured_addrs /* 0 if none or not found */,
276 const struct comm_addr *incoming_packet_addr /* 0 if none */);
278 /* Called if we are the responder in a key setup, when the resolve
279 * completes. transport_compute_setupinit_peers will hvae been called
280 * earlier. If _complete is called, we are still doing the key setup
281 * (and we should use the new values for both the rest of the key
282 * setup and the ongoing data exchange); if _tardy is called, the key
283 * setup is done (either completed or not) and only the data peers are
285 static void transport_resolve_complete(struct site *st,
286 const struct comm_addr *addrs, int naddrs);
287 static void transport_resolve_complete_tardy(struct site *st,
288 const struct comm_addr *addrs, int naddrs);
290 static void transport_xmit(struct site *st, transport_peers *peers,
291 struct buffer_if *buf, bool_t candebug);
293 /***** END of transport peers declarations *****/
297 struct transform_inst_if *transform;
298 uint64_t key_timeout; /* End of life of current key */
299 uint32_t remote_session_id;
305 /* configuration information */
309 bool_t local_mobile, peer_mobile; /* Mobile client support */
310 int32_t transport_peers_max;
311 string_t tunname; /* localname<->remotename by default, used in logs */
312 cstring_t *addresses; /* DNS name or address(es) for bootstrapping, optional */
313 int remoteport; /* Port for bootstrapping, optional */
315 struct netlink_if *netlink;
316 struct comm_if **comms;
317 struct comm_clientinfo **commclientinfos;
319 struct resolver_if *resolver;
321 struct random_if *random;
322 struct privcache_if *privkeys;
323 struct sigprivkey_if *privkey_fixed;
324 struct transform_if **transforms;
328 uint32_t index; /* Index of this site */
329 uint32_t early_capabilities;
330 uint32_t local_capabilities;
331 int32_t setup_retries; /* How many times to send setup packets */
332 int32_t setup_retry_interval; /* Initial timeout for setup packets */
333 int32_t wait_timeout_mean; /* How long to wait if setup unsuccessful */
334 int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
335 int32_t key_lifetime; /* How long a key lasts once set up */
336 int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
337 after this time, initiate a new
340 bool_t our_name_later; /* our name > peer name */
343 /* runtime information */
345 uint64_t now; /* Most recently seen time */
346 bool_t allow_send_prod;
347 bool_t msg1_crossed_logged;
349 int resolving_n_results_all;
350 int resolving_n_results_stored;
351 struct comm_addr resolving_results[MAX_PEER_ADDRS];
352 const char *peerkeys_path;
353 struct pathprefix_template peerkeys_tmpl;
354 struct peer_keyset *peerkeys_current, *peerkeys_kex;
356 /* The currently established session */
357 struct data_key current;
358 struct data_key auxiliary_key;
359 bool_t auxiliary_is_new;
360 uint64_t renegotiate_key_time; /* When we can negotiate a new key */
361 uint64_t auxiliary_renegotiate_key_time;
362 transport_peers peers; /* Current address(es) of peer for data traffic */
364 /* The current key setup protocol exchange. We can only be
365 involved in one of these at a time. There's a potential for
366 denial of service here (the attacker keeps sending a setup
367 packet; we keep trying to continue the exchange, and have to
368 timeout before we can listen for another setup packet); perhaps
369 we should keep a list of 'bad' sources for setup packets. */
370 uint32_t remote_capabilities;
371 uint16_t remote_adv_mtu;
372 struct transform_if *chosen_transform;
373 uint32_t setup_session_id;
374 transport_peers setup_peers;
375 uint8_t localN[NONCELEN]; /* Nonces for key exchange */
376 uint8_t remoteN[NONCELEN];
377 struct buffer_if buffer; /* Current outgoing key exchange packet */
378 struct buffer_if scratch;
379 int32_t retries; /* Number of retries remaining */
380 uint64_t timeout; /* Timeout for current state */
382 uint8_t *sharedsecret;
383 uint32_t sharedsecretlen, sharedsecretallocd;
384 struct transform_inst_if *new_transform; /* For key setup/verify */
387 static uint32_t event_log_priority(struct site *st, uint32_t event)
389 if (!(event&st->log_events))
392 case LOG_UNEXPECTED: return M_INFO;
393 case LOG_SETUP_INIT: return M_INFO;
394 case LOG_SETUP_TIMEOUT: return M_NOTICE;
395 case LOG_ACTIVATE_KEY: return M_INFO;
396 case LOG_TIMEOUT_KEY: return M_INFO;
397 case LOG_SEC: return M_SECURITY;
398 case LOG_STATE: return M_DEBUG;
399 case LOG_DROP: return M_DEBUG;
400 case LOG_DUMP: return M_DEBUG;
401 case LOG_ERROR: return M_ERR;
402 case LOG_PEER_ADDRS: return M_DEBUG;
403 case LOG_SIGKEYS: return M_INFO;
404 default: return M_ERR;
408 static uint32_t slog_start(struct site *st, uint32_t event)
410 uint32_t class=event_log_priority(st, event);
412 slilog_part(st->log,class,"%s: ",st->tunname);
417 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
419 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
423 class=slog_start(st,event);
425 vslilog_part(st->log,class,msg,ap);
426 slilog_part(st->log,class,"\n");
430 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
432 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
436 vslog(st,event,msg,ap);
440 static void logtimeout(struct site *st, const char *fmt, ...)
442 static void logtimeout(struct site *st, const char *fmt, ...)
444 uint32_t class=event_log_priority(st,LOG_SETUP_TIMEOUT);
451 slilog_part(st->log,class,"%s: ",st->tunname);
452 vslilog_part(st->log,class,fmt,ap);
456 for (i=0, delim=" (tried ";
457 i<st->setup_peers.npeers;
459 transport_peer *peer=&st->setup_peers.peers[i];
460 const char *s=comm_addr_to_string(&peer->addr);
461 slilog_part(st->log,class,"%s%s",delim,s);
464 slilog_part(st->log,class,")\n");
468 static void set_link_quality(struct site *st);
469 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
470 static void delete_one_key(struct site *st, struct data_key *key,
471 const char *reason /* may be 0 meaning don't log*/,
472 const char *which /* ignored if !reasonn */,
473 uint32_t loglevel /* ignored if !reasonn */);
474 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
475 const struct comm_addr *prod_hint);
476 static void enter_state_run(struct site *st);
477 static bool_t enter_state_resolve(struct site *st);
478 static void decrement_resolving_count(struct site *st, int by);
479 static bool_t enter_new_state(struct site *st,uint32_t next,
480 const struct msg *prompt
481 /* may be 0 for SENTMSG1 */);
482 static void enter_state_wait(struct site *st);
483 static void activate_new_key(struct site *st);
485 static bool_t is_transform_valid(struct transform_inst_if *transform)
487 return transform && transform->valid(transform->st);
490 static bool_t current_valid(struct site *st)
492 return is_transform_valid(st->current.transform);
495 #define DEFINE_CALL_TRANSFORM(fwdrev) \
496 static transform_apply_return \
497 call_transform_##fwdrev(struct site *st, \
498 struct transform_inst_if *transform, \
499 struct buffer_if *buf, \
500 const char **errmsg) \
502 if (!is_transform_valid(transform)) { \
503 *errmsg="transform not set up"; \
504 return transform_apply_err; \
506 return transform->fwdrev(transform->st,buf,errmsg); \
509 DEFINE_CALL_TRANSFORM(forwards)
510 DEFINE_CALL_TRANSFORM(reverse)
512 static void dispose_transform(struct transform_inst_if **transform_var)
514 struct transform_inst_if *transform=*transform_var;
516 transform->delkey(transform->st);
517 transform->destroy(transform->st);
522 #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
523 #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
524 #define CHECK_TYPE(b,t) do { uint32_t type; \
525 CHECK_AVAIL((b),4); \
526 type=buf_unprepend_uint32((b)); \
527 if (type!=(t)) return False; } while(0)
529 static _Bool type_is_msg23(uint32_t type)
532 case LABEL_MSG2: case CASES_MSG3_KNOWN: return True;
533 default: return False;
536 static _Bool type_is_msg34(uint32_t type)
539 case CASES_MSG3_KNOWN: case LABEL_MSG4: return True;
540 default: return False;
547 struct buffer_if extrainfo;
554 struct parsedname remote;
555 struct parsedname local;
556 uint32_t remote_capabilities;
558 int capab_transformnum;
564 struct alg_msg_data sig;
565 int n_pubkeys_accepted_nom; /* may be > MAX_SIG_KEYS ! */
566 const struct sigkeyid *pubkeys_accepted[MAX_SIG_KEYS];
567 int signing_key_index;
570 static const struct sigkeyid keyid_zero;
572 static int32_t wait_timeout(struct site *st) {
573 int32_t t = st->wait_timeout_mean;
576 st->random->generate(st->random->st,sizeof(factor),&factor);
577 t += (t / 256) * factor;
582 static _Bool set_new_transform(struct site *st, char *pk)
586 /* Make room for the shared key */
587 st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
588 assert(st->sharedsecretlen);
589 if (st->sharedsecretlen > st->sharedsecretallocd) {
590 st->sharedsecretallocd=st->sharedsecretlen;
591 st->sharedsecret=safe_realloc_ary(st->sharedsecret,1,
592 st->sharedsecretallocd,
593 "site:sharedsecret");
596 /* Generate the shared key */
597 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,pk,
598 st->sharedsecret,st->sharedsecretlen);
600 /* Set up the transform */
601 struct transform_if *generator=st->chosen_transform;
602 struct transform_inst_if *generated=generator->create(generator->st);
603 ok = generated->setkey(generated->st,st->sharedsecret,
604 st->sharedsecretlen,st->our_name_later);
606 dispose_transform(&st->new_transform);
607 if (!ok) return False;
608 st->new_transform=generated;
610 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
611 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
612 st->chosen_transform->capab_bit,
613 st->local_capabilities, st->remote_capabilities);
618 int32_t lenpos, afternul;
620 static void append_string_xinfo_start(struct buffer_if *buf,
621 struct xinfoadd *xia,
623 /* Helps construct one of the names with additional info as found
624 * in MSG1..4. Call this function first, then append all the
625 * desired extra info (not including the nul byte) to the buffer,
626 * then call append_string_xinfo_done. */
628 xia->lenpos = buf->size;
629 buf_append_string(buf,str);
630 buf_append_uint8(buf,0);
631 xia->afternul = buf->size;
633 static void append_string_xinfo_done(struct buffer_if *buf,
634 struct xinfoadd *xia)
636 /* we just need to adjust the string length */
637 if (buf->size == xia->afternul) {
638 /* no extra info, strip the nul too */
639 buf_unappend_uint8(buf);
641 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
645 /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
646 out using a transform of config data supplied by netlink */
647 static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what,
648 const struct msg *prompt
649 /* may be 0 for MSG1 */)
655 st->retries=st->setup_retries;
656 BUF_ALLOC(&st->buffer,what);
657 buffer_init(&st->buffer,0);
658 buf_append_uint32(&st->buffer,
659 (type==LABEL_MSG1?0:st->setup_session_id));
660 buf_append_uint32(&st->buffer,st->index);
661 buf_append_uint32(&st->buffer,type);
664 append_string_xinfo_start(&st->buffer,&xia,st->localname);
665 buf_append_uint32(&st->buffer,st->local_capabilities);
666 if (type_is_msg34(type)) {
667 buf_append_uint16(&st->buffer,st->mtu_target);
669 if (type_is_msg23(type)) {
670 buf_append_uint8(&st->buffer,st->peerkeys_kex->nkeys);
671 for (ki=0; ki<st->peerkeys_kex->nkeys; ki++) {
672 struct peer_pubkey *pk = &st->peerkeys_kex->keys[ki];
673 BUF_ADD_OBJ(append,&st->buffer,pk->id);
676 struct sigprivkey_if *privkey=0;
677 if (type_is_msg34(type)) {
678 assert(prompt->n_pubkeys_accepted_nom>0);
680 ki<prompt->n_pubkeys_accepted_nom && ki<MAX_SIG_KEYS;
682 const struct sigkeyid *kid=prompt->pubkeys_accepted[ki];
684 privkey=st->privkeys->lookup(st->privkeys->st,kid,st->log);
685 if (privkey) goto privkey_found;
687 if (sigkeyid_equal(&keyid_zero,kid)) {
688 privkey=st->privkey_fixed;
693 uint32_t class = slog_start(st,LOG_ERROR);
695 slilog_part(st->log,class,"no suitable private key, peer wanted");
697 ki<prompt->n_pubkeys_accepted_nom && ki<MAX_SIG_KEYS;
699 slilog_part(st->log,class, " " SIGKEYID_PR_FMT,
700 SIGKEYID_PR_VAL(prompt->pubkeys_accepted[ki]));
702 if (prompt->n_pubkeys_accepted_nom > MAX_SIG_KEYS)
703 slilog_part(st->log,class," +%d",
704 prompt->n_pubkeys_accepted_nom - MAX_SIG_KEYS);
705 slilog_part(st->log,class,"\n");
710 slog(st,LOG_SIGKEYS,"using private key #%d " SIGKEYID_PR_FMT,
711 ki, SIGKEYID_PR_VAL(prompt->pubkeys_accepted[ki]));
712 buf_append_uint8(&st->buffer,ki);
715 append_string_xinfo_done(&st->buffer,&xia);
717 buf_append_string(&st->buffer,st->remotename);
718 BUF_ADD_OBJ(append,&st->buffer,st->localN);
719 if (type==LABEL_MSG1) return True;
720 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
721 if (type==LABEL_MSG2) return True;
723 if (hacky_par_mid_failnow()) return False;
725 if (MSGMAJOR(type) == 3) do {
726 minor = MSGMINOR(type);
727 if (minor < 1) break;
728 buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
731 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
732 buf_append_string(&st->buffer,dhpub);
735 bool_t ok=privkey->sign(privkey->st,
746 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
749 nm->len=buf_unprepend_uint16(msg);
750 CHECK_AVAIL(msg,nm->len);
751 nm->name=buf_unprepend(msg,nm->len);
752 uint8_t *nul=memchr(nm->name,0,nm->len);
754 buffer_readonly_view(&nm->extrainfo,0,0);
756 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
757 nm->len=nul-nm->name;
762 static bool_t unpick_msg(struct site *st, uint32_t type,
763 struct buffer_if *msg, struct msg *m)
767 m->n_pubkeys_accepted_nom=-1;
768 m->capab_transformnum=-1;
769 m->signing_key_index=-1;
770 m->hashstart=msg->start;
772 m->dest=buf_unprepend_uint32(msg);
774 m->source=buf_unprepend_uint32(msg);
775 CHECK_TYPE(msg,type);
776 if (!unpick_name(msg,&m->remote)) return False;
777 m->remote_capabilities=0;
779 if (m->remote.extrainfo.size) {
780 CHECK_AVAIL(&m->remote.extrainfo,4);
781 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
783 if (type_is_msg34(type) && m->remote.extrainfo.size) {
784 CHECK_AVAIL(&m->remote.extrainfo,2);
785 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
787 if (type_is_msg23(type) && m->remote.extrainfo.size) {
788 m->n_pubkeys_accepted_nom = buf_unprepend_uint8(&m->remote.extrainfo);
789 if (!m->n_pubkeys_accepted_nom) return False;
790 for (int ki_nom=0; ki_nom<m->n_pubkeys_accepted_nom; ki_nom++) {
791 CHECK_AVAIL(&m->remote.extrainfo,KEYIDSZ);
792 struct sigkeyid *kid = buf_unprepend(&m->remote.extrainfo,KEYIDSZ);
793 if (ki_nom<MAX_SIG_KEYS) m->pubkeys_accepted[ki_nom] = kid;
796 m->n_pubkeys_accepted_nom = 1;
797 m->pubkeys_accepted[0] = &keyid_zero;
799 if (type_is_msg34(type) && m->remote.extrainfo.size) {
800 m->signing_key_index=buf_unprepend_uint8(&m->remote.extrainfo);
802 m->signing_key_index=0;
804 if (!unpick_name(msg,&m->local)) return False;
805 if (type==LABEL_PROD) {
809 CHECK_AVAIL(msg,NONCELEN);
810 m->nR=buf_unprepend(msg,NONCELEN);
811 if (type==LABEL_MSG1) {
815 CHECK_AVAIL(msg,NONCELEN);
816 m->nL=buf_unprepend(msg,NONCELEN);
817 if (type==LABEL_MSG2) {
821 if (MSGMAJOR(type) == 3) do {
822 minor = MSGMINOR(type);
823 #define MAYBE_READ_CAP(minminor, kind, dflt) do { \
824 if (minor < (minminor)) \
825 m->capab_##kind##num = (dflt); \
827 CHECK_AVAIL(msg, 1); \
828 m->capab_##kind##num = buf_unprepend_uint8(msg); \
831 MAYBE_READ_CAP(1, transform, CAPAB_BIT_ANCIENTTRANSFORM);
832 #undef MAYBE_READ_CAP
835 m->pklen=buf_unprepend_uint16(msg);
836 CHECK_AVAIL(msg,m->pklen);
837 m->pk=buf_unprepend(msg,m->pklen);
838 m->hashlen=msg->start-m->hashstart;
840 if (m->signing_key_index < 0 ||
841 m->signing_key_index >= st->peerkeys_kex->nkeys) {
844 struct sigpubkey_if *pubkey=
845 st->peerkeys_kex->keys[m->signing_key_index].pubkey;
846 if (!pubkey->unpick(pubkey->st,msg,&m->sig)) {
855 static bool_t name_matches(const struct parsedname *nm, const char *expected)
857 int expected_len=strlen(expected);
859 nm->len == expected_len &&
860 !memcmp(nm->name, expected, expected_len);
863 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
866 if (type==LABEL_MSG1) return True;
868 /* Check that the site names and our nonce have been sent
869 back correctly, and then store our peer's nonce. */
870 if (!name_matches(&m->remote,st->remotename)) {
871 *error="wrong remote site name";
874 if (!name_matches(&m->local,st->localname)) {
875 *error="wrong local site name";
878 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
879 *error="wrong locally-generated nonce";
882 if (type==LABEL_MSG2) return True;
883 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
884 *error="wrong remotely-generated nonce";
887 /* MSG3 has complicated rules about capabilities, which are
888 * handled in process_msg3. */
889 if (MSGMAJOR(type) == 3) return True;
890 if (m->remote_capabilities!=st->remote_capabilities) {
891 *error="remote capabilities changed";
894 if (type==LABEL_MSG4) return True;
895 *error="unknown message type";
899 static void peerkeys_maybe_incorporate(struct site *st, const char *file,
900 const char *whatmore,
903 struct peer_keyset *atsuffix=
904 keyset_load(file,&st->scratch,st->log,logcl_enoent);
905 if (!atsuffix) return;
907 if (st->peerkeys_current &&
908 serial_cmp(atsuffix->serial,st->peerkeys_current->serial) <= 0) {
909 slog(st,LOG_SIGKEYS,"keys from %s%s are older, discarding",
911 keyset_dispose(&atsuffix);
913 if (r) slog(st,LOG_ERROR,"failed to remove old key update %s: %s\n",
914 st->peerkeys_tmpl.buffer,strerror(errno));
917 slog(st,LOG_SIGKEYS,"keys from %s%s are newer, installing",
919 keyset_dispose(&st->peerkeys_current);
920 st->peerkeys_current=atsuffix;
921 int r=rename(file,st->peerkeys_path);
922 if (r) slog(st,LOG_ERROR,"failed to install key update %s as %s: %s\n",
923 st->peerkeys_tmpl.buffer,st->peerkeys_path,
928 static void peerkeys_check_for_update(struct site *st)
930 if (!st->peerkeys_path) return;
932 pathprefix_template_setsuffix(&st->peerkeys_tmpl,"~proc");
933 peerkeys_maybe_incorporate(st,st->peerkeys_tmpl.buffer,
934 " (found old update)",
937 pathprefix_template_setsuffix(&st->peerkeys_tmpl,"~update");
938 const char *inputp=st->peerkeys_tmpl.buffer;
939 if (access(inputp,R_OK)) {
941 slog(st,LOG_ERROR,"cannot access peer key update file %s\n",
946 buffer_init(&st->scratch,0);
947 BUF_ADD_BYTES(append,&st->scratch,
948 st->peerkeys_tmpl.buffer,
949 strlen(st->peerkeys_tmpl.buffer)+1);
950 inputp=st->scratch.start;
952 pathprefix_template_setsuffix(&st->peerkeys_tmpl,"~proc");
953 const char *oursp=st->peerkeys_tmpl.buffer;
955 int r=rename(inputp,oursp);
957 slog(st,LOG_ERROR,"failed to claim key update file %s as %s: %s",
958 inputp,oursp,strerror(errno));
962 peerkeys_maybe_incorporate(st,oursp," (update)",M_ERR);
966 static bool_t kex_init(struct site *st)
968 keyset_dispose(&st->peerkeys_kex);
969 peerkeys_check_for_update(st);
970 if (!st->peerkeys_current) {
971 slog(st,LOG_SETUP_INIT,"no peer public keys, abandoning key setup");
974 st->peerkeys_kex = keyset_dup(st->peerkeys_current);
975 st->random->generate(st->random->st,NONCELEN,st->localN);
979 static bool_t generate_msg1(struct site *st, const struct msg *prompt_maybe_0)
982 generate_msg(st,LABEL_MSG1,"site:MSG1",prompt_maybe_0);
985 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
986 const struct comm_addr *src,
989 /* We've already determined we're in an appropriate state to
990 process an incoming MSG1, and that the MSG1 has correct values
993 st->setup_session_id=m->source;
994 st->remote_capabilities=m->remote_capabilities;
995 memcpy(st->remoteN,m->nR,NONCELEN);
999 static bool_t generate_msg2(struct site *st,
1000 const struct msg *prompt_may_be_null)
1003 generate_msg(st,LABEL_MSG2,"site:MSG2",prompt_may_be_null);
1006 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
1007 const struct comm_addr *src,
1008 struct msg *m /* returned */)
1012 if (!unpick_msg(st,LABEL_MSG2,msg2,m)) return False;
1013 if (!check_msg(st,LABEL_MSG2,m,&err)) {
1014 slog(st,LOG_SEC,"msg2: %s",err);
1017 st->setup_session_id=m->source;
1018 st->remote_capabilities=m->remote_capabilities;
1020 /* Select the transform to use */
1022 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
1023 if (!remote_crypto_caps)
1024 /* old secnets only had this one transform */
1025 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
1027 #define CHOOSE_CRYPTO(kind, whats) do { \
1028 struct kind##_if *iface; \
1029 uint32_t bit, ours = 0; \
1031 for (i= 0; i < st->n##kind##s; i++) { \
1032 iface=st->kind##s[i]; \
1033 bit = 1UL << iface->capab_bit; \
1034 if (bit & remote_crypto_caps) goto kind##_found; \
1037 slog(st,LOG_ERROR,"no " whats " in common" \
1038 " (us %#"PRIx32"; them: %#"PRIx32")", \
1039 st->local_capabilities & ours, remote_crypto_caps); \
1042 st->chosen_##kind = iface; \
1045 CHOOSE_CRYPTO(transform, "transforms");
1047 #undef CHOOSE_CRYPTO
1049 memcpy(st->remoteN,m->nR,NONCELEN);
1053 static bool_t generate_msg3(struct site *st, const struct msg *prompt)
1055 /* Now we have our nonce and their nonce. Think of a secret key,
1056 and create message number 3. */
1057 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
1058 return generate_msg(st,
1059 (st->remote_capabilities & CAPAB_TRANSFORM_MASK)
1062 "site:MSG3",prompt);
1065 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
1067 /* Check signature and store g^x mod m */
1070 if (m->signing_key_index >= 0) {
1071 if (m->signing_key_index >= st->peerkeys_kex->nkeys)
1073 ki=m->signing_key_index;
1075 for (ki=0; ki<st->peerkeys_kex->nkeys; ki++)
1076 if (sigkeyid_equal(&keyid_zero,&st->peerkeys_kex->keys[ki].id))
1080 "peer signed with keyid zero, which we do not accept");
1084 struct sigpubkey_if *pubkey=st->peerkeys_kex->keys[ki].pubkey;
1086 if (!pubkey->check(pubkey->st,
1087 m->hashstart,m->hashlen,
1089 slog(st,LOG_SEC,"msg3/msg4 signature failed check!"
1090 " (key #%d " SIGKEYID_PR_FMT ")",
1091 ki, SIGKEYID_PR_VAL(&st->peerkeys_kex->keys[ki].id));
1094 slog(st,LOG_SIGKEYS,"verified peer signature with key #%d "
1095 SIGKEYID_PR_FMT, ki,
1096 SIGKEYID_PR_VAL(&st->peerkeys_kex->keys[ki].id));
1098 st->remote_adv_mtu=m->remote_mtu;
1103 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
1104 const struct comm_addr *src, uint32_t msgtype,
1105 struct msg *m /* returned */)
1110 case CASES_MSG3_KNOWN: break;
1114 if (!unpick_msg(st,msgtype,msg3,m)) return False;
1115 if (!check_msg(st,msgtype,m,&err)) {
1116 slog(st,LOG_SEC,"msg3: %s",err);
1119 uint32_t capab_adv_late = m->remote_capabilities
1120 & ~st->remote_capabilities & st->early_capabilities;
1121 if (capab_adv_late) {
1122 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
1123 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
1124 capab_adv_late, st->remote_capabilities, m->remote_capabilities);
1128 #define CHOSE_CRYPTO(kind, what) do { \
1129 struct kind##_if *iface; \
1131 for (i=0; i<st->n##kind##s; i++) { \
1132 iface=st->kind##s[i]; \
1133 if (iface->capab_bit == m->capab_##kind##num) \
1134 goto kind##_found; \
1136 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
1137 m->capab_##kind##num); \
1140 st->chosen_##kind=iface; \
1143 CHOSE_CRYPTO(transform, "transform");
1147 if (!process_msg3_msg4(st,m))
1150 /* Update our idea of the remote site's capabilities, now that we've
1151 * verified that its message was authentic.
1153 * Our previous idea of the remote site's capabilities came from the
1154 * unauthenticated MSG1. We've already checked that this new message
1155 * doesn't change any of the bits we relied upon in the past, but it may
1156 * also have set additional capability bits. We simply throw those away
1157 * now, and use the authentic capabilities from this MSG3. */
1158 st->remote_capabilities=m->remote_capabilities;
1160 /* Terminate their DH public key with a '0' */
1162 /* Invent our DH secret key */
1163 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
1165 /* Generate the shared key and set up the transform */
1166 if (!set_new_transform(st,m->pk)) return False;
1171 static bool_t generate_msg4(struct site *st, const struct msg *prompt)
1173 /* We have both nonces, their public key and our private key. Generate
1174 our public key, sign it and send it to them. */
1175 return generate_msg(st,LABEL_MSG4,"site:MSG4",prompt);
1178 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
1179 const struct comm_addr *src,
1180 struct msg *m /* returned */)
1184 if (!unpick_msg(st,LABEL_MSG4,msg4,m)) return False;
1185 if (!check_msg(st,LABEL_MSG4,m,&err)) {
1186 slog(st,LOG_SEC,"msg4: %s",err);
1190 if (!process_msg3_msg4(st,m))
1193 /* Terminate their DH public key with a '0' */
1196 /* Generate the shared key and set up the transform */
1197 if (!set_new_transform(st,m->pk)) return False;
1208 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1211 CHECK_AVAIL(msg0,4);
1212 m->dest=buf_unprepend_uint32(msg0);
1213 CHECK_AVAIL(msg0,4);
1214 m->source=buf_unprepend_uint32(msg0);
1215 CHECK_AVAIL(msg0,4);
1216 m->type=buf_unprepend_uint32(msg0);
1218 /* Leaves transformed part of buffer untouched */
1221 static bool_t generate_msg5(struct site *st, const struct msg *prompt)
1223 cstring_t transform_err;
1225 BUF_ALLOC(&st->buffer,"site:MSG5");
1226 /* We are going to add four words to the message */
1227 buffer_init(&st->buffer,calculate_max_start_pad());
1228 /* Give the netlink code an opportunity to put its own stuff in the
1229 message (configuration information, etc.) */
1230 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1231 if (call_transform_forwards(st,st->new_transform,
1232 &st->buffer,&transform_err))
1234 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1235 buf_prepend_uint32(&st->buffer,st->index);
1236 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1238 st->retries=st->setup_retries;
1242 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1243 const struct comm_addr *src,
1244 struct transform_inst_if *transform)
1247 cstring_t transform_err;
1249 if (!unpick_msg0(st,msg5,&m)) return False;
1251 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1252 /* There's a problem */
1253 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1256 /* Buffer should now contain untransformed PING packet data */
1257 CHECK_AVAIL(msg5,4);
1258 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1259 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1262 /* Older versions of secnet used to write some config data here
1263 * which we ignore. So we don't CHECK_EMPTY */
1267 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1268 uint32_t session_id)
1270 cstring_t transform_err;
1272 BUF_ALLOC(&st->buffer,"site:MSG6");
1273 /* We are going to add four words to the message */
1274 buffer_init(&st->buffer,calculate_max_start_pad());
1275 /* Give the netlink code an opportunity to put its own stuff in the
1276 message (configuration information, etc.) */
1277 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1278 transform_apply_return problem =
1279 call_transform_forwards(st,transform,
1280 &st->buffer,&transform_err);
1282 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1283 buf_prepend_uint32(&st->buffer,st->index);
1284 buf_prepend_uint32(&st->buffer,session_id);
1287 static bool_t generate_msg6(struct site *st, const struct msg *prompt)
1289 if (!is_transform_valid(st->new_transform))
1291 create_msg6(st,st->new_transform,st->setup_session_id);
1292 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1296 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1297 const struct comm_addr *src)
1300 cstring_t transform_err;
1302 if (!unpick_msg0(st,msg6,&m)) return False;
1304 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1305 /* There's a problem */
1306 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1309 /* Buffer should now contain untransformed PING packet data */
1310 CHECK_AVAIL(msg6,4);
1311 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1312 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1315 /* Older versions of secnet used to write some config data here
1316 * which we ignore. So we don't CHECK_EMPTY */
1320 static transform_apply_return
1321 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1322 const struct comm_addr *src)
1324 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1326 transform_apply_return problem;
1328 if (!unpick_msg0(st,msg0,&m)) return False;
1330 /* Keep a copy so we can try decrypting it with multiple keys */
1331 buffer_copy(&st->scratch, msg0);
1333 problem = call_transform_reverse(st,st->current.transform,
1334 msg0,&transform_err);
1336 if (!st->auxiliary_is_new)
1337 delete_one_key(st,&st->auxiliary_key,
1338 "peer has used new key","auxiliary key",LOG_SEC);
1341 if (transform_apply_return_badseq(problem))
1344 buffer_copy(msg0, &st->scratch);
1345 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1348 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1349 if (st->auxiliary_is_new) {
1350 /* We previously timed out in state SENTMSG5 but it turns
1351 * out that our peer did in fact get our MSG5 and is
1352 * using the new key. So we should switch to it too. */
1353 /* This is a bit like activate_new_key. */
1356 st->current=st->auxiliary_key;
1357 st->auxiliary_key=t;
1359 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1360 "previous key",LOG_SEC);
1361 st->auxiliary_is_new=0;
1362 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1366 if (transform_apply_return_badseq(problem))
1369 if (st->state==SITE_SENTMSG5) {
1370 buffer_copy(msg0, &st->scratch);
1371 problem = call_transform_reverse(st,st->new_transform,
1374 /* It looks like we didn't get the peer's MSG6 */
1375 /* This is like a cut-down enter_new_state(SITE_RUN) */
1376 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1377 BUF_FREE(&st->buffer);
1379 activate_new_key(st);
1380 return 0; /* do process the data in this packet */
1382 if (transform_apply_return_badseq(problem))
1386 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1387 transform_err,auxkey_err,newkey_err);
1388 initiate_key_setup(st,"incoming message would not decrypt",0);
1389 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1394 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1399 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1400 const struct comm_addr *src)
1403 transform_apply_return problem;
1405 problem = decrypt_msg0(st,msg0,src);
1406 if (problem==transform_apply_seqdupe) {
1407 /* We recently received another copy of this packet, maybe due
1408 * to polypath. That's not a problem; indeed, for the
1409 * purposes of transport address management it is a success.
1410 * But we don't want to process the packet. */
1411 transport_data_msgok(st,src);
1417 CHECK_AVAIL(msg0,4);
1418 type=buf_unprepend_uint32(msg0);
1421 /* We must forget about the current session. */
1422 delete_keys(st,"request from peer",LOG_SEC);
1423 /* probably, the peer is shutting down, and this is going to fail,
1424 * but we need to be trying to bring the link up again */
1426 initiate_key_setup(st,"peer requested key teardown",0);
1429 /* Deliver to netlink layer */
1430 st->netlink->deliver(st->netlink->st,msg0);
1431 transport_data_msgok(st,src);
1432 /* See whether we should start negotiating a new key */
1433 if (st->now > st->renegotiate_key_time)
1434 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1437 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1444 static void dump_packet(struct site *st, struct buffer_if *buf,
1445 const struct comm_addr *addr, bool_t incoming,
1448 uint32_t dest=get_uint32(buf->start);
1449 uint32_t source=get_uint32(buf->start+4);
1450 uint32_t msgtype=get_uint32(buf->start+8);
1452 if (st->log_events & LOG_DUMP)
1453 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1454 st->tunname,incoming?"incoming":"outgoing",
1455 dest,source,msgtype,comm_addr_to_string(addr),
1459 static bool_t comm_addr_sendmsg(struct site *st,
1460 const struct comm_addr *dest,
1461 struct buffer_if *buf)
1464 struct comm_clientinfo *commclientinfo = 0;
1466 for (i=0; i < st->ncomms; i++) {
1467 if (st->comms[i] == dest->comm) {
1468 commclientinfo = st->commclientinfos[i];
1472 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1475 static uint32_t site_status(void *st)
1480 static bool_t send_msg(struct site *st)
1482 if (st->retries>0) {
1483 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1484 st->timeout=st->now+st->setup_retry_interval;
1487 } else if (st->state==SITE_SENTMSG5) {
1488 logtimeout(st,"timed out sending MSG5, stashing new key");
1489 /* We stash the key we have produced, in case it turns out that
1490 * our peer did see our MSG5 after all and starts using it. */
1491 /* This is a bit like some of activate_new_key */
1492 struct transform_inst_if *t;
1493 t=st->auxiliary_key.transform;
1494 st->auxiliary_key.transform=st->new_transform;
1495 st->new_transform=t;
1496 dispose_transform(&st->new_transform);
1498 st->auxiliary_is_new=1;
1499 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1500 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1501 st->auxiliary_key.remote_session_id=st->setup_session_id;
1503 enter_state_wait(st);
1506 logtimeout(st,"timed out sending key setup packet "
1507 "(in state %s)",state_name(st->state));
1508 enter_state_wait(st);
1513 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1514 int stored_naddrs, int all_naddrs,
1515 const char *address, const char *failwhy)
1517 struct site *st=sst;
1519 if (!stored_naddrs) {
1520 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1522 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1523 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1525 int space=st->transport_peers_max-st->resolving_n_results_stored;
1526 int n_tocopy=MIN(stored_naddrs,space);
1527 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1530 st->resolving_n_results_stored += n_tocopy;
1531 st->resolving_n_results_all += all_naddrs;
1534 decrement_resolving_count(st,1);
1537 static void decrement_resolving_count(struct site *st, int by)
1539 assert(st->resolving_count>0);
1540 st->resolving_count-=by;
1542 if (st->resolving_count)
1545 /* OK, we are done with them all. Handle combined results. */
1547 const struct comm_addr *addrs=st->resolving_results;
1548 int naddrs=st->resolving_n_results_stored;
1549 assert(naddrs<=st->transport_peers_max);
1552 if (naddrs != st->resolving_n_results_all) {
1553 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1554 " yielded too many results (%d > %d), some ignored",
1555 st->resolving_n_results_all, naddrs);
1557 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1558 naddrs, iaddr_to_string(&addrs[0].ia));;
1561 switch (st->state) {
1563 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1564 enter_new_state(st,SITE_SENTMSG1,0);
1566 /* Can't figure out who to try to to talk to */
1567 slog(st,LOG_SETUP_INIT,
1568 "key exchange failed: cannot find peer address");
1569 enter_state_run(st);
1572 case SITE_SENTMSG1: case SITE_SENTMSG2:
1573 case SITE_SENTMSG3: case SITE_SENTMSG4:
1576 /* We start using the address immediately for data too.
1577 * It's best to store it in st->peers now because we might
1578 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1579 * the new key (without updating the data peer addrs). */
1580 transport_resolve_complete(st,addrs,naddrs);
1581 } else if (st->local_mobile) {
1582 /* We can't let this rest because we may have a peer
1583 * address which will break in the future. */
1584 slog(st,LOG_SETUP_INIT,"resolution failed: "
1585 "abandoning key exchange");
1586 enter_state_wait(st);
1588 slog(st,LOG_SETUP_INIT,"resolution failed: "
1589 " continuing to use source address of peer's packets"
1590 " for key exchange and ultimately data");
1595 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1596 " updating peer address(es)");
1597 transport_resolve_complete_tardy(st,addrs,naddrs);
1598 } else if (st->local_mobile) {
1599 /* Not very good. We should queue (another) renegotiation
1600 * so that we can update the peer address. */
1601 st->key_renegotiate_time=st->now+wait_timeout(st);
1603 slog(st,LOG_SETUP_INIT,"resolution failed: "
1604 " continuing to use source address of peer's packets");
1614 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1615 const struct comm_addr *prod_hint)
1617 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1618 if (st->state!=SITE_RUN) return False;
1619 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1620 if (st->addresses) {
1621 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1622 return enter_state_resolve(st);
1623 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1624 return enter_new_state(st,SITE_SENTMSG1,0);
1626 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1630 static void activate_new_key(struct site *st)
1632 struct transform_inst_if *t;
1634 /* We have three transform instances, which we swap between old,
1636 t=st->auxiliary_key.transform;
1637 st->auxiliary_key.transform=st->current.transform;
1638 st->current.transform=st->new_transform;
1639 st->new_transform=t;
1640 dispose_transform(&st->new_transform);
1643 st->auxiliary_is_new=0;
1644 st->auxiliary_key.key_timeout=st->current.key_timeout;
1645 st->current.key_timeout=st->now+st->key_lifetime;
1646 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1647 transport_peers_copy(st,&st->peers,&st->setup_peers);
1648 st->current.remote_session_id=st->setup_session_id;
1650 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1651 * But their mtu be unspecified, in which case we just use ours. */
1652 uint32_t intersite_mtu=
1653 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1654 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1656 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1657 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1658 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1659 enter_state_run(st);
1662 static void delete_one_key(struct site *st, struct data_key *key,
1663 cstring_t reason, cstring_t which, uint32_t loglevel)
1665 if (!is_transform_valid(key->transform)) return;
1666 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1667 dispose_transform(&key->transform);
1671 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1673 if (current_valid(st)) {
1674 slog(st,loglevel,"session closed (%s)",reason);
1676 delete_one_key(st,&st->current,0,0,0);
1677 set_link_quality(st);
1679 delete_one_key(st,&st->auxiliary_key,0,0,0);
1682 static void state_assert(struct site *st, bool_t ok)
1684 if (!ok) fatal("site:state_assert");
1687 static void enter_state_stop(struct site *st)
1689 st->state=SITE_STOP;
1691 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1692 dispose_transform(&st->new_transform);
1695 static void set_link_quality(struct site *st)
1698 if (current_valid(st))
1699 quality=LINK_QUALITY_UP;
1700 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1701 quality=LINK_QUALITY_DOWN;
1702 else if (st->addresses)
1703 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1704 else if (transport_peers_valid(&st->peers))
1705 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1707 quality=LINK_QUALITY_DOWN;
1709 st->netlink->set_quality(st->netlink->st,quality);
1712 static void enter_state_run(struct site *st)
1714 slog(st,LOG_STATE,"entering state RUN%s",
1715 current_valid(st) ? " (keyed)" : " (unkeyed)");
1719 st->setup_session_id=0;
1720 transport_peers_clear(st,&st->setup_peers);
1721 keyset_dispose(&st->peerkeys_kex);
1722 FILLZERO(st->localN);
1723 FILLZERO(st->remoteN);
1724 dispose_transform(&st->new_transform);
1725 memset(st->dhsecret,0,st->dh->len);
1726 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1727 set_link_quality(st);
1729 if (st->keepalive && !current_valid(st))
1730 initiate_key_setup(st, "keepalive", 0);
1733 static bool_t ensure_resolving(struct site *st)
1735 /* Reentrancy hazard: may call site_resolve_callback and hence
1736 * enter_new_state, enter_state_* and generate_msg*. */
1737 if (st->resolving_count)
1740 assert(st->addresses);
1742 /* resolver->request might reentrantly call site_resolve_callback
1743 * which will decrement st->resolving, so we need to increment it
1744 * twice beforehand to prevent decrement from thinking we're
1745 * finished, and decrement it ourselves. Alternatively if
1746 * everything fails then there are no callbacks due and we simply
1747 * set it to 0 and return false.. */
1748 st->resolving_n_results_stored=0;
1749 st->resolving_n_results_all=0;
1750 st->resolving_count+=2;
1751 const char **addrp=st->addresses;
1752 const char *address;
1754 for (; (address=*addrp++); ) {
1755 bool_t ok = st->resolver->request(st->resolver->st,address,
1756 st->remoteport,st->comms[0],
1757 site_resolve_callback,st);
1759 st->resolving_count++;
1763 st->resolving_count=0;
1766 decrement_resolving_count(st,2);
1770 static bool_t enter_state_resolve(struct site *st)
1772 /* Reentrancy hazard! See ensure_resolving. */
1773 state_assert(st,st->state==SITE_RUN);
1774 slog(st,LOG_STATE,"entering state RESOLVE");
1775 st->state=SITE_RESOLVE;
1776 return ensure_resolving(st);
1779 static bool_t enter_new_state(struct site *st, uint32_t next,
1780 const struct msg *prompt
1781 /* may be 0 for SENTMSG1 */)
1783 bool_t (*gen)(struct site *st, const struct msg *prompt);
1786 slog(st,LOG_STATE,"entering state %s",state_name(next));
1789 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1790 if (!kex_init(st)) return False;
1792 st->msg1_crossed_logged = False;
1795 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1796 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1797 if (!kex_init(st)) return False;
1801 state_assert(st,st->state==SITE_SENTMSG1);
1802 BUF_FREE(&st->buffer);
1806 state_assert(st,st->state==SITE_SENTMSG2);
1807 BUF_FREE(&st->buffer);
1811 state_assert(st,st->state==SITE_SENTMSG3);
1812 BUF_FREE(&st->buffer);
1816 state_assert(st,st->state==SITE_SENTMSG4);
1817 BUF_FREE(&st->buffer);
1822 fatal("enter_new_state(%s): invalid new state",state_name(next));
1826 if (hacky_par_start_failnow()) return False;
1828 r= gen(st,prompt) && send_msg(st);
1831 st->setup_retries, st->setup_retry_interval,
1836 if (next==SITE_RUN) {
1837 BUF_FREE(&st->buffer); /* Never reused */
1838 st->timeout=0; /* Never retransmit */
1839 activate_new_key(st);
1843 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1844 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1845 in either state, and enter_state_wait() will
1847 enter_state_wait(st);
1851 /* msg7 tells our peer that we're about to forget our key */
1852 static bool_t send_msg7(struct site *st, cstring_t reason)
1854 cstring_t transform_err;
1856 if (current_valid(st) && st->buffer.free
1857 && transport_peers_valid(&st->peers)) {
1858 BUF_ALLOC(&st->buffer,"site:MSG7");
1859 buffer_init(&st->buffer,calculate_max_start_pad());
1860 buf_append_uint32(&st->buffer,LABEL_MSG7);
1861 buf_append_string(&st->buffer,reason);
1862 if (call_transform_forwards(st, st->current.transform,
1863 &st->buffer, &transform_err))
1865 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1866 buf_prepend_uint32(&st->buffer,st->index);
1867 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1868 transport_xmit(st,&st->peers,&st->buffer,True);
1869 BUF_FREE(&st->buffer);
1876 /* We go into this state if our peer becomes uncommunicative. Similar to
1877 the "stop" state, we forget all session keys for a while, before
1878 re-entering the "run" state. */
1879 static void enter_state_wait(struct site *st)
1881 slog(st,LOG_STATE,"entering state WAIT");
1882 st->timeout=st->now+wait_timeout(st);
1883 st->state=SITE_WAIT;
1884 set_link_quality(st);
1885 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1886 /* XXX Erase keys etc. */
1889 static void generate_prod(struct site *st, struct buffer_if *buf)
1892 buf_append_uint32(buf,0);
1893 buf_append_uint32(buf,0);
1894 buf_append_uint32(buf,LABEL_PROD);
1895 buf_append_string(buf,st->localname);
1896 buf_append_string(buf,st->remotename);
1899 static void generate_send_prod(struct site *st,
1900 const struct comm_addr *source)
1902 if (!st->allow_send_prod) return; /* too soon */
1903 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1904 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1906 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1907 st->allow_send_prod=0;
1908 generate_prod(st,&st->scratch);
1909 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1910 dump_packet(st,&st->scratch,source,False,ok);
1913 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1916 int64_t offset=timeout-*now;
1917 if (offset<0) offset=0;
1918 if (offset>INT_MAX) offset=INT_MAX;
1919 if (*timeout_io<0 || offset<*timeout_io)
1924 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1927 struct site *st=sst;
1929 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1932 /* Work out when our next timeout is. The earlier of 'timeout' or
1933 'current.key_timeout'. A stored value of '0' indicates no timeout
1935 site_settimeout(st->timeout, timeout_io);
1936 site_settimeout(st->current.key_timeout, timeout_io);
1937 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1939 return 0; /* success */
1942 static void check_expiry(struct site *st, struct data_key *key,
1945 if (key->key_timeout && *now>key->key_timeout) {
1946 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1950 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1951 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1953 struct site *st=sst;
1956 if (st->timeout && *now>st->timeout) {
1958 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1959 if (!hacky_par_start_failnow())
1961 } else if (st->state==SITE_WAIT) {
1962 enter_state_run(st);
1964 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1968 check_expiry(st,&st->current,"current key");
1969 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1972 /* This function is called by the netlink device to deliver packets
1973 intended for the remote network. The packet is in "raw" wire
1974 format, but is guaranteed to be word-aligned. */
1975 static void site_outgoing(void *sst, struct buffer_if *buf)
1977 struct site *st=sst;
1978 cstring_t transform_err;
1980 if (st->state==SITE_STOP) {
1985 st->allow_send_prod=1;
1987 /* In all other states we consider delivering the packet if we have
1988 a valid key and a valid address to send it to. */
1989 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1990 /* Transform it and send it */
1992 buf_prepend_uint32(buf,LABEL_MSG9);
1993 if (call_transform_forwards(st, st->current.transform,
1994 buf, &transform_err))
1996 buf_prepend_uint32(buf,LABEL_MSG0);
1997 buf_prepend_uint32(buf,st->index);
1998 buf_prepend_uint32(buf,st->current.remote_session_id);
1999 transport_xmit(st,&st->peers,buf,False);
2006 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
2008 initiate_key_setup(st,"outgoing packet",0);
2011 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
2012 uint32_t type, struct msg *m,
2013 struct priomsg *whynot)
2014 /* For packets which are identified by the local and remote names.
2015 * If it has our name and our peer's name in it it's for us. */
2017 struct buffer_if buf[1];
2018 buffer_readonly_clone(buf,buf_in);
2020 if (!unpick_msg(st,type,buf,m)) {
2021 priomsg_update_fixed(whynot, comm_notify_whynot_unpick, "malformed");
2024 #define NAME_MATCHES(lr) \
2025 if (!name_matches(&m->lr, st->lr##name)) { \
2026 if (priomsg_update_fixed(whynot, comm_notify_whynot_name_##lr, \
2027 "unknown " #lr " name: ")) { \
2028 truncmsg_add_packet_string(&whynot->m, m->lr.len, m->lr.name); \
2032 NAME_MATCHES(remote);
2033 NAME_MATCHES(local );
2039 static bool_t we_have_priority(struct site *st, const struct msg *m) {
2040 if (st->local_capabilities & m->remote_capabilities &
2041 CAPAB_PRIORITY_MOBILE) {
2042 if (st->local_mobile) return True;
2043 if (st-> peer_mobile) return False;
2045 return st->our_name_later;
2048 static bool_t setup_late_msg_ok(struct site *st,
2049 const struct buffer_if *buf_in,
2051 const struct comm_addr *source,
2052 struct msg *m /* returned */) {
2053 /* For setup packets which seem from their type like they are
2054 * late. Maybe they came via a different path. All we do is make
2055 * a note of the sending address, iff they look like they are part
2056 * of the current key setup attempt. */
2057 if (!named_for_us(st,buf_in,msgtype,m,0))
2058 /* named_for_us calls unpick_msg which gets the nonces */
2060 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN) ||
2061 !consttime_memeq(m->nL,st->localN, NONCELEN))
2062 /* spoof ? from stale run ? who knows */
2064 transport_setup_msgok(st,source);
2068 /* This function is called by the communication device to deliver
2069 packets from our peers.
2070 It should return True if the packet is recognised as being for
2071 this current site instance (and should therefore not be processed
2072 by other sites), even if the packet was otherwise ignored. */
2073 static bool_t site_incoming(void *sst, struct buffer_if *buf,
2074 const struct comm_addr *source,
2075 struct priomsg *whynot)
2077 struct site *st=sst;
2079 if (buf->size < 12) return False;
2081 uint32_t dest=get_uint32(buf->start);
2082 uint32_t msgtype=get_uint32(buf->start+8);
2084 /* initialised by named_for_us, or process_msgN for N!=1 */
2086 if (msgtype==LABEL_MSG1) {
2087 if (!named_for_us(st,buf,msgtype,&msg,whynot))
2089 /* It's a MSG1 addressed to us. Decide what to do about it. */
2090 dump_packet(st,buf,source,True,True);
2091 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
2092 st->state==SITE_WAIT) {
2093 /* We should definitely process it */
2094 transport_compute_setupinit_peers(st,0,0,source);
2095 if (process_msg1(st,buf,source,&msg)) {
2096 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
2097 bool_t entered=enter_new_state(st,SITE_SENTMSG2,&msg);
2098 if (entered && st->addresses && st->local_mobile)
2099 /* We must do this as the very last thing, because
2100 the resolver callback might reenter us. */
2101 ensure_resolving(st);
2103 slog(st,LOG_ERROR,"failed to process incoming msg1");
2107 } else if (st->state==SITE_SENTMSG1) {
2108 /* We've just sent a message 1! They may have crossed on
2109 the wire. If we have priority then we ignore the
2110 incoming one, otherwise we process it as usual. */
2111 if (we_have_priority(st,&msg)) {
2113 if (!st->msg1_crossed_logged++)
2114 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
2115 "priority => ignore incoming msg1");
2118 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
2119 "priority => use incoming msg1");
2120 if (process_msg1(st,buf,source,&msg)) {
2121 BUF_FREE(&st->buffer); /* Free our old message 1 */
2122 transport_setup_msgok(st,source);
2123 enter_new_state(st,SITE_SENTMSG2,&msg);
2125 slog(st,LOG_ERROR,"failed to process an incoming "
2126 "crossed msg1 (we have low priority)");
2131 } else if (st->state==SITE_SENTMSG2 ||
2132 st->state==SITE_SENTMSG4) {
2133 if (consttime_memeq(msg.nR,st->remoteN,NONCELEN)) {
2134 /* We are ahead in the protocol, but that msg1 had the
2135 * peer's nonce so presumably it is from this key
2136 * exchange run, via a slower route */
2137 transport_setup_msgok(st,source);
2139 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
2144 /* The message 1 was received at an unexpected stage of the
2145 key setup. Well, they lost the race. */
2146 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
2150 if (msgtype==LABEL_PROD) {
2151 if (!named_for_us(st,buf,msgtype,&msg,whynot))
2153 dump_packet(st,buf,source,True,True);
2154 if (st->state!=SITE_RUN) {
2155 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
2156 } else if (current_valid(st)) {
2157 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
2159 initiate_key_setup(st,"peer sent PROD packet",source);
2164 if (dest==st->index) {
2165 /* Explicitly addressed to us */
2166 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
2169 /* If the source is our current peer then initiate a key setup,
2170 because our peer's forgotten the key */
2171 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
2173 initiated = initiate_key_setup(st,"received a NAK",source);
2174 if (!initiated) generate_send_prod(st,source);
2176 slog(st,LOG_SEC,"bad incoming NAK");
2180 process_msg0(st,buf,source);
2183 /* Setup packet: should not have been explicitly addressed
2185 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
2188 /* Setup packet: expected only in state SENTMSG1 */
2189 if (st->state!=SITE_SENTMSG1) {
2190 if ((st->state==SITE_SENTMSG3 ||
2191 st->state==SITE_SENTMSG5) &&
2192 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2194 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
2195 } else if (process_msg2(st,buf,source,&msg)) {
2196 transport_setup_msgok(st,source);
2197 enter_new_state(st,SITE_SENTMSG3,&msg);
2199 slog(st,LOG_SEC,"invalid MSG2");
2202 case CASES_MSG3_KNOWN:
2203 /* Setup packet: expected only in state SENTMSG2 */
2204 if (st->state!=SITE_SENTMSG2) {
2205 if ((st->state==SITE_SENTMSG4) &&
2206 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2208 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
2209 } else if (process_msg3(st,buf,source,msgtype,&msg)) {
2210 transport_setup_msgok(st,source);
2211 enter_new_state(st,SITE_SENTMSG4,&msg);
2213 slog(st,LOG_SEC,"invalid MSG3");
2217 /* Setup packet: expected only in state SENTMSG3 */
2218 if (st->state!=SITE_SENTMSG3) {
2219 if ((st->state==SITE_SENTMSG5) &&
2220 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2222 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
2223 } else if (process_msg4(st,buf,source,&msg)) {
2224 transport_setup_msgok(st,source);
2225 enter_new_state(st,SITE_SENTMSG5,&msg);
2227 slog(st,LOG_SEC,"invalid MSG4");
2231 /* Setup packet: expected only in state SENTMSG4 */
2232 /* (may turn up in state RUN if our return MSG6 was lost
2233 and the new key has already been activated. In that
2234 case we discard it. The peer will realise that we
2235 are using the new key when they see our data packets.
2236 Until then the peer's data packets to us get discarded. */
2237 if (st->state==SITE_SENTMSG4) {
2238 if (process_msg5(st,buf,source,st->new_transform)) {
2239 transport_setup_msgok(st,source);
2240 enter_new_state(st,SITE_RUN,&msg);
2242 slog(st,LOG_SEC,"invalid MSG5");
2244 } else if (st->state==SITE_RUN) {
2245 if (process_msg5(st,buf,source,st->current.transform)) {
2246 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2247 transport_setup_msgok(st,source);
2248 create_msg6(st,st->current.transform,
2249 st->current.remote_session_id);
2250 transport_xmit(st,&st->peers,&st->buffer,True);
2251 BUF_FREE(&st->buffer);
2253 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2256 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2260 /* Setup packet: expected only in state SENTMSG5 */
2261 if (st->state!=SITE_SENTMSG5) {
2262 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2263 } else if (process_msg6(st,buf,source)) {
2264 BUF_FREE(&st->buffer); /* Free message 5 */
2265 transport_setup_msgok(st,source);
2266 activate_new_key(st);
2268 slog(st,LOG_SEC,"invalid MSG6");
2272 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2280 priomsg_update_fixed(whynot, comm_notify_whynot_general,
2281 "not MSG1 or PROD; unknown dest index");
2285 static void site_control(void *vst, bool_t run)
2287 struct site *st=vst;
2288 if (run) enter_state_run(st);
2289 else enter_state_stop(st);
2292 static void site_phase_hook(void *sst, uint32_t newphase)
2294 struct site *st=sst;
2296 /* The program is shutting down; tell our peer */
2297 send_msg7(st,"shutting down");
2300 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2302 struct site *st=sst;
2303 dispose_transform(&st->current.transform);
2304 dispose_transform(&st->auxiliary_key.transform);
2305 dispose_transform(&st->new_transform);
2306 /* Not much point overwiting the signing key, since we loaded it
2307 from disk, and it is only valid prospectively if at all,
2309 /* XXX it would be best to overwrite the DH state, because that
2310 _is_ relevant to forward secrecy. However we have no
2311 convenient interface for doing that and in practice gmp has
2312 probably dribbled droppings all over the malloc arena. A good
2313 way to fix this would be to have a privsep child for asymmetric
2314 crypto operations, but that's a task for another day. */
2317 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2320 static uint32_t index_sequence;
2328 st->cl.description="site";
2329 st->cl.type=CL_SITE;
2331 st->cl.interface=&st->ops;
2333 st->ops.control=site_control;
2334 st->ops.status=site_status;
2335 st->peerkeys_path=0;
2336 st->peerkeys_tmpl.buffer=0;
2337 st->peerkeys_current=st->peerkeys_kex=0;
2339 /* First parameter must be a dict */
2340 item=list_elem(args,0);
2341 if (!item || item->type!=t_dict)
2342 cfgfatal(loc,"site","parameter must be a dictionary\n");
2344 dict=item->data.dict;
2345 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2346 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2347 log_event_table,"site");
2349 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2350 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2352 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2354 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2356 /* Now slog is working */
2358 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2360 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2362 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2364 /* Sanity check (which also allows the 'sites' file to include
2365 site() closures for all sites including our own): refuse to
2366 talk to ourselves */
2367 if (strcmp(st->localname,st->remotename)==0) {
2368 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2370 if (st->peer_mobile != st->local_mobile)
2371 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2372 " but our local-mobile=%d\n",
2373 st->localname, st->peer_mobile, st->local_mobile);
2377 if (st->peer_mobile && st->local_mobile) {
2378 Message(M_WARNING,"site %s: site is mobile but so are we"
2379 " -> ignoring this site\n", st->remotename);
2384 assert(index_sequence < 0xffffffffUL);
2385 st->index = ++index_sequence;
2386 st->local_capabilities = 0;
2387 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2388 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2390 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2391 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2392 if (!things##_cfg) \
2393 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2394 st->nthings=list_length(things##_cfg); \
2395 NEW_ARY(st->things,st->nthings); \
2396 assert(st->nthings); \
2397 for (i=0; i<st->nthings; i++) { \
2398 item_t *item=list_elem(things##_cfg,i); \
2399 if (item->type!=t_closure) \
2400 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2401 closure_t *cl=item->data.closure; \
2402 if (cl->type!=CL_TYPE) \
2403 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2404 st->things[i]=cl->interface; \
2408 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2410 NEW_ARY(st->commclientinfos, st->ncomms);
2411 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2412 for (i=0; i<st->ncomms; i++) {
2413 st->commclientinfos[i] =
2415 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2418 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2419 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2421 st->privkeys=find_cl_if(dict,"key-cache",CL_PRIVCACHE,False,"site",loc);
2422 if (!st->privkeys) {
2424 find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2427 struct sigpubkey_if *fixed_pubkey
2428 =find_cl_if(dict,"key",CL_SIGPUBKEY,False,"site",loc);
2429 st->peerkeys_path=dict_read_string(dict,"peer-keys",fixed_pubkey==0,
2431 if (st->peerkeys_path) {
2432 pathprefix_template_init(&st->peerkeys_tmpl,st->peerkeys_path,
2433 PEERKEYS_SUFFIX_MAXLEN + 1 /* nul */);
2434 st->peerkeys_current=keyset_load(st->peerkeys_path,
2435 &st->scratch,st->log,M_ERR);
2437 fixed_pubkey->dispose(fixed_pubkey->st);
2440 assert(fixed_pubkey);
2441 NEW(st->peerkeys_current);
2442 st->peerkeys_current->refcount=1;
2443 st->peerkeys_current->nkeys=1;
2444 st->peerkeys_current->keys[0].id=keyid_zero;
2445 st->peerkeys_current->keys[0].pubkey=fixed_pubkey;
2446 slog(st,LOG_SIGKEYS,
2447 "using old-style fixed peer public key (no `peer-keys')");
2450 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2452 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2453 else st->remoteport=0;
2455 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2457 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2459 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2460 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2461 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2463 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2464 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2465 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2466 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2467 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2469 st->mobile_peer_expiry= dict_read_number(
2470 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2472 const char *peerskey= st->peer_mobile
2473 ? "mobile-peers-max" : "static-peers-max";
2474 st->transport_peers_max= dict_read_number(
2475 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2476 if (st->transport_peers_max<1 ||
2477 st->transport_peers_max>MAX_PEER_ADDRS) {
2478 cfgfatal(loc,"site", "%s must be in range 1.."
2479 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2482 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2483 st->key_renegotiate_time=st->key_lifetime/2;
2485 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2486 st->key_renegotiate_time=dict_read_number(
2487 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2488 if (st->key_renegotiate_time > st->key_lifetime) {
2489 cfgfatal(loc,"site",
2490 "renegotiate-time must be less than key-lifetime\n");
2493 st->resolving_count=0;
2494 st->allow_send_prod=0;
2496 /* The information we expect to see in incoming messages of type 1 */
2497 /* fixme: lots of unchecked overflows here, but the results are only
2498 corrupted packets rather than undefined behaviour */
2499 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2501 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2503 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2504 BUF_ALLOC(&st->scratch,"site:scratch");
2506 /* We are interested in poll(), but only for timeouts. We don't have
2507 any fds of our own. */
2508 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2511 st->remote_capabilities=0;
2512 st->chosen_transform=0;
2513 st->current.key_timeout=0;
2514 st->auxiliary_key.key_timeout=0;
2515 transport_peers_clear(st,&st->peers);
2516 transport_peers_clear(st,&st->setup_peers);
2517 /* XXX mlock these */
2518 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2519 st->sharedsecretlen=st->sharedsecretallocd=0;
2522 #define SET_CAPBIT(bit) do { \
2523 uint32_t capflag = 1UL << (bit); \
2524 if (st->local_capabilities & capflag) \
2525 slog(st,LOG_ERROR,"capability bit" \
2526 " %d (%#"PRIx32") reused", (bit), capflag); \
2527 st->local_capabilities |= capflag; \
2530 for (i=0; i<st->ntransforms; i++)
2531 SET_CAPBIT(st->transforms[i]->capab_bit);
2535 if (st->local_mobile || st->peer_mobile)
2536 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2538 /* We need to register the remote networks with the netlink device */
2539 uint32_t netlink_mtu; /* local virtual interface mtu */
2540 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2541 if (!st->mtu_target)
2542 st->mtu_target=netlink_mtu;
2544 for (i=0; i<st->ncomms; i++)
2545 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2547 st->current.transform=0;
2548 st->auxiliary_key.transform=0;
2549 st->new_transform=0;
2550 st->auxiliary_is_new=0;
2552 enter_state_stop(st);
2554 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2555 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2557 return new_closure(&st->cl);
2560 void site_module(dict_t *dict)
2562 add_closure(dict,"site",site_apply);
2566 /***** TRANSPORT PEERS definitions *****/
2568 static void transport_peers_debug(struct site *st, transport_peers *dst,
2569 const char *didwhat,
2570 int nargs, const struct comm_addr *args,
2575 if (!(st->log_events & LOG_PEER_ADDRS))
2576 return; /* an optimisation */
2578 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2579 (dst==&st->peers ? "data" :
2580 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2581 didwhat, nargs, dst->npeers);
2583 for (i=0, argp=(void*)args;
2585 i++, (argp+=stride?stride:sizeof(*args))) {
2586 const struct comm_addr *ca=(void*)argp;
2587 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2588 i, comm_addr_to_string(ca));
2590 for (i=0; i<dst->npeers; i++) {
2591 struct timeval diff;
2592 timersub(tv_now,&dst->peers[i].last,&diff);
2593 const struct comm_addr *ca=&dst->peers[i].addr;
2594 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2595 i, comm_addr_to_string(ca),
2596 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2600 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2601 /* peers must be sorted first */
2602 if (st->local_mobile) return;
2604 int previous_peers=peers->npeers;
2605 struct timeval oldest;
2606 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2607 oldest.tv_usec = tv_now->tv_usec;
2608 while (peers->npeers>1 &&
2609 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2611 if (peers->npeers != previous_peers)
2612 transport_peers_debug(st,peers,"expire", 0,0,0);
2615 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2616 const struct comm_addr *ca,
2617 const struct timeval *tv) {
2618 /* returns false if output is full */
2621 if (peers->npeers >= st->transport_peers_max)
2624 for (search=0; search<peers->npeers; search++)
2625 if (comm_addr_equal(&peers->peers[search].addr, ca))
2628 peers->peers[peers->npeers].addr = *ca;
2629 peers->peers[peers->npeers].last = *tv;
2634 static void transport_record_peers(struct site *st, transport_peers *peers,
2635 const struct comm_addr *addrs, int naddrs,
2637 /* We add addrs into peers. The new entries end up at the front
2638 * and displace entries towards the end (perhaps even off the
2639 * end). Any existing matching entries are moved up to the front.
2641 * Caller must first call transport_peers_expire. */
2644 /* avoids debug for uninteresting updates */
2646 for (i=0; i<peers->npeers; i++) {
2647 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2648 memmove(peers->peers+1, peers->peers,
2649 sizeof(peers->peers[0]) * i);
2650 peers->peers[0].addr = addrs[0];
2651 peers->peers[0].last = *tv_now;
2657 int old_npeers=peers->npeers;
2658 transport_peer old_peers[old_npeers];
2659 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2663 for (i=0; i<naddrs; i++) {
2664 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2667 for (i=0; i<old_npeers; i++) {
2668 const transport_peer *old=&old_peers[i];
2669 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2673 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2676 static void transport_expire_record_peers(struct site *st,
2677 transport_peers *peers,
2678 const struct comm_addr *addrs,
2679 int naddrs, const char *m) {
2680 /* Convenience function */
2681 transport_peers_expire(st,peers);
2682 transport_record_peers(st,peers,addrs,naddrs,m);
2685 static bool_t transport_compute_setupinit_peers(struct site *st,
2686 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2687 int n_configured_addrs /* 0 if none or not found */,
2688 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2689 if (!n_configured_addrs && !incoming_packet_addr &&
2690 !transport_peers_valid(&st->peers))
2693 slog(st,LOG_SETUP_INIT,
2694 "using: %d configured addr(s);%s %d old peer addrs(es)",
2696 incoming_packet_addr ? " incoming packet address;" : "",
2699 /* Non-mobile peers try addresses until one is plausible. The
2700 * effect is that this code always tries first the configured
2701 * address if supplied, or otherwise the address of the incoming
2702 * PROD, or finally the existing data peer if one exists; this is
2705 transport_peers_copy(st,&st->setup_peers,&st->peers);
2706 transport_peers_expire(st,&st->setup_peers);
2708 if (incoming_packet_addr)
2709 transport_record_peers(st,&st->setup_peers,
2710 incoming_packet_addr,1, "incoming");
2712 if (n_configured_addrs)
2713 transport_record_peers(st,&st->setup_peers,
2714 configured_addrs,n_configured_addrs, "setupinit");
2716 assert(transport_peers_valid(&st->setup_peers));
2720 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2721 if (st->peer_mobile)
2722 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2724 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2725 if (st->peer_mobile)
2726 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2729 static int transport_peers_valid(transport_peers *peers) {
2730 return peers->npeers;
2732 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2734 transport_peers_debug(st,peers,"clear",0,0,0);
2736 static void transport_peers_copy(struct site *st, transport_peers *dst,
2737 const transport_peers *src) {
2738 dst->npeers=src->npeers;
2739 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2740 transport_peers_debug(st,dst,"copy",
2741 src->npeers, &src->peers->addr, sizeof(*src->peers));
2744 static void transport_resolve_complete(struct site *st,
2745 const struct comm_addr *addrs,
2747 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2749 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2753 static void transport_resolve_complete_tardy(struct site *st,
2754 const struct comm_addr *addrs,
2756 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2757 "resolved tardily");
2760 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2762 const transport_peers *inp) {
2763 /* out and in->peers may be the same region, or nonoverlapping */
2764 const transport_peer *in=inp->peers;
2766 for (slot=0; slot<inp->npeers; slot++) {
2767 if (!(mask & (1U << slot)))
2769 if (!(out==in && slot==*nout_io))
2770 COPY_OBJ(out[*nout_io], in[slot]);
2775 void transport_xmit(struct site *st, transport_peers *peers,
2776 struct buffer_if *buf, bool_t candebug) {
2778 transport_peers_expire(st, peers);
2779 unsigned failed=0; /* bitmask */
2780 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2783 for (slot=0; slot<peers->npeers; slot++) {
2784 transport_peer *peer=&peers->peers[slot];
2785 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2787 dump_packet(st, buf, &peer->addr, False, ok);
2789 failed |= 1U << slot;
2792 if (ok && !st->peer_mobile)
2795 /* Now we need to demote/delete failing addrs: if we are mobile we
2796 * merely demote them; otherwise we delete them. */
2797 if (st->local_mobile) {
2798 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2799 /* `expected' has all the failures at the end already */
2800 if (failed != expected) {
2802 transport_peer failedpeers[nfailed];
2803 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2804 assert(fslot == nfailed);
2806 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2807 assert(wslot+nfailed == peers->npeers);
2808 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2809 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2812 if (failed && peers->npeers > 1) {
2814 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2815 peers->npeers=wslot;
2816 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2821 /***** END of transport peers declarations *****/